On Thu, Feb 21, 2019 at 03:02:57PM -0500, Mathieu Desnoyers wrote: > Hi Arnd, Russell, Linus, > > Can we ensure the arm32 kprobes fix I submitted gets upstream before 5.0 > final ? > It takes care of an illegal instruction issue with optimized kprobes on arm32. > > Here is the current state of default kprobes configuration on arm32: > using them will trigger illegal instruction OOPS on v5.0-rc7, 4.19.24, > v4.14.102. > > My fix is in "accepted" state in the arm patch tracking system: > > https://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8834/1 > > Should I send it directly to Linus as well ?
Accepted means it's in my tree pending to be sent to Linus. It should now be in mainline. Have you checked? > > Thanks, > > Mathieu > > ----- On Feb 18, 2019, at 9:55 AM, Mathieu Desnoyers > [email protected] wrote: > > > ----- On Feb 18, 2019, at 7:26 AM, Greg Kroah-Hartman > > [email protected] > > wrote: > > > >> On Wed, Feb 06, 2019 at 01:41:15PM +0900, Masami Hiramatsu wrote: > >>> On Tue, 5 Feb 2019 15:06:10 +0000 > >>> Kees Cook <[email protected]> wrote: > >>> > >>> > On Mon, Feb 4, 2019 at 7:15 PM Mathieu Desnoyers > >>> > <[email protected]> wrote: > >>> > > > >>> > > Hi, > >>> > > > >>> > > I notice this commit as a possible culprit of the illegal > >>> > > instructions my lttng > >>> > > users are noticing on arm32 when using kprobes on a v4.19.13 Linux > >>> > > kernel > >>> > > in a Yocto environment [1]. They were able to reproduce the issue > >>> > > with perf > >>> > > as well. > >>> > > > >>> > > commit e46daee53bb50bde38805f1823a182979724c229 > >>> > > Author: Kees Cook <[email protected]> > >>> > > Date: Tue Oct 30 22:12:56 2018 +0100 > >>> > > > >>> > > ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCE > >>> > > > >>> > > I *think* the intent there was to do > >>> > > > >>> > > - memcpy(code, &optprobe_template_entry, > >>> > > + memcpy(code, (unsigned long *)&optprobe_template_entry, > >>> > > > >>> > > But if you look at the commit, the "&" seems to have been stripped > >>> > > away, > >>> > > which happens to change the behavior significantly. > >>> > > >>> > Yeah, this was a typo on my part. :( > >>> > >>> Ah, I thought it had been fixed as same as x86. > >>> On x86, all optprobe_template_* are defined as kprobe_opcode_t [], > >>> but on arm, it still be kprobe_opcode_t. > >>> > >>> Hmm, but I think we should use kprobe_opcode_t [] or char[] as > >>> asm/sections.h > >>> does. > >>> OK, I'll prepare for the change. > >> > >> Did this ever get fixed in Linus's tree? If so, what is the git commit > >> id, I can't seem to find anything... > > > > It seems to still be in the arm patch tracking system: > > > > https://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8834/1 > > > > If I understand its status correctly, it is applied to the arm tree, but > > perhaps it has not been pulled by Linus yet ? The code is still broken > > in Linus' master. > > > > It would be important to get this arm kprobes fix upstream before 5.0 > > final. > > > > Thanks, > > > > Mathieu > > > > > > -- > > Mathieu Desnoyers > > EfficiOS Inc. > > http://www.efficios.com > > -- > Mathieu Desnoyers > EfficiOS Inc. > http://www.efficios.com > -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up
